U4256BM-RSG3
| Model | U4256BM-RSG3 |
| Description | Frequency Synthesizer for Radio Tuning |
| PDF file | Total 19 pages (File size: 386K) |
| Chip Manufacturer | ATMEL |
Features
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Reference Oscillator up to 15 MHz (Tuned)
Oscillator Buffer Output (for AM Up/Down Conversion)
Two Programmable 16-bit Dividers
Fine-tuning Steps Possible
Fast Response Time due to Integrated Loop Push-pull Stage
3-wire Bus (Enable, Clock and Data; 3 V and 5 V Microcontrollers Acceptable)
Four Programmable Switching Outputs (Open Drain)
Three DACs for Software Controlled Tuner Alignment
Low-power Consumption
High S/N Ratio
Integrated Band Gap – only One Supply Voltage Necessary
Description
The U4256BM-R is a synthesizer IC for FM receivers and an AM up-convertion
system in BICMOS technology. Together with the AM/FM IC T4258 or U4255BM, it
performs a complete AM/FM car radio front-end, which is recommended also for RDS
(Radio Data System) applications. It is controlled by a 3-wire bus and also contains
switches and Digital to Analog Converters (DACs) for software-controlled alignment of
the AM/FM tuner. The U4256BM-R is the pin-compatible succesor IC of U4256BM-N.
Frequency
Synthesizer for
Radio Tuning
U4256BM-R
Preliminary
Pin Configuration
Figure 1.
Pinning SSO20
FMOSCIN
OSCOUT
12
SWO3
9
GNDan
MX2LO
OSCIN
DATA
CLK
20
19
18
17
16
15
U4256BM-R
14
13
DAC1
SWO4 10
1
4
5
2
3
SWO1 7
PD
6
SWO2
DAC2
PDO
DAC3
VS
8
11 GND
EN
V5
Rev. 4562C–AUDR–08/04
1
